Evaluation of intrayolk sac inoculation of Infectious bursal disease vaccine on immune Responses in newly hatched broiler chicks

الملخص EN

A total of 60 one-day old Ross broiler chicks were used in this study.

The birds were divided into four groups.

The first group A was vaccinated against IBD with a Cevac IBD L vaccine at one-day old by intra-yolk sac method (lYS) with a dose of 0.5ml using a (1ml) syringe, whereas the second group B was vaccinated against IBD with the same vaccine at 14 days of age by drinking water method (DW).

The third group C and fourth group D were considered as a positive and negative control respectively .

On day 35, the birds were weight and killed to collect blood samples and lymphoid organs were removed and weight to study the effects of (lYS) rout on body weight , lymphoid organ weights and the humeral immune response to IBD vaccine which measured by ELISA test.

The results showed significant differences at (P≤0.05) in body weight of group A, in addition significant (p<0.05) increase in the all lymphoid organs weight , Bursa of fabricius (BF) was 1.643 a ±0.066 in group comparison with other groups which had been recorded 1.102 b ±0.022, 0.850 c ±0.067 in group B and C respectively.

Group B indicated that was a significant decrease at (p<0.05) in the weight of of spleen which was 1.102 b ± 0.022 in comparison to control groups.

With regard to serological test, bird from group A recorded higher Ab titer 24038 a± 685 compared to those of other groups , and this increment was statically significant (p<0.05), however both group A and B revealed a significant differences( p <0.05) from the control groups.

Generally the results indicated that intra-yolk sac method was highly effective rout of IBD vaccine administration.